About Novint Falcon Novint Falcon : 3-DOF, Impedance type Haptic Device. Mechanism used is modified delta mechanism. Cost : 150$ only….. Performance : Varies from device to device, due to cheap motors, cheap encoders etc. But really cheap device for any beginner to start his/her research work. Cool device to play games and have real force feedback. Courtesy of :

Our Initial Goals Our Initial Goals To improve the performance of the device by implementing Gravity and Friction Compensation.

How far have we reached? How far have we reached? We did implemented the Gravity Compensation, by computing it’s Kinematics, calculating COM, forming Jacobian Matrix, calculating the masses and then calculating & giving the force output to the device. We already have the dynamics calculated for the device.

Approach Initially, we proceeded with the paper on : Delta robot: inverse, direct, and intermediate Jacobians by M Lo´pez1, E Castillo, G Garcı´a, and A Bashir We computed Kinematics using this paper. Fig. Original Delta Mechanism Courtesy of: text.pdf

Calculating COM

Calculating Moment of Inertia using Bifilar Pendulum Method

Movies Without Gravity Compensation With Gravity Compensation

The major turnaround!!! We later on, found online a Ph.D. Thesis Report of R.E. Stamper on “A Three Degree of Freedom Parallel Manipulator with Only Translational Degrees of Freedom”. We found that the work what we were trying to do was already done way back!!! Gravity and Friction Compensation both were already done.

Further Modifications We made few modifications in our original Inverse Kinematic Equations, based on modified delta mechanism. Jacobian Matrix and Gravity Compensation implemented from the Phd Paper with further modifications.

How were we same?? Fig. Modified Delta Mechanism used in the Phd paper Courtesy of: Courtesy of: age/PhD_97-4.pdf

How were we different?? Assumptions being made. Falcon mechanism is different, than the Thesis Paper in two ways. Direction of Gravity Force Courtesy of : Courtesy of : owimage/PhD_97-4.pdf

Goals being modified!!! Building a 5-DOF device using 2-Falcons.

Alternative available in the Market Courtesy of : Quanser HD^2 High-Definition Haptic Device. It’s an 5-DOF Device. Cost : $70, Courtesy of:

What can be the cheaper alternative??? Build an 5-DOF Haptic Device using two Falcons. Cost : 320$ [2 Falcons + $20] Performance : Improved by our Gravity Compensation. Courtesy of: upload.wikimedia.org

Software Open Source software available at Chai3d Beta Version 2.0 Visual Studio 2003 or above is required. OpenGl & Microsoft SDk are required. Latest Novint Drivers from

Future Goals Implementing Friction Compensation, to make device feel much better. Make the current code more efficient. Make new virtual environments.

Information about DEMO Gravity Compensation working for the New 5-DOF Device. Few Virtual Environments to interact.

Thank You. Any Questions??? Courtesy of :

Computing Inverse Kinematics float theta33_1 = acos((px*sin(phi_1)/bb + py*cos(phi_1)/bb)); float theta33_2 = acos((px*sin(phi_2)/bb + py*cos(phi_2)/bb)); float theta33_3 = acos((px*sin(phi_3)/bb + py*cos(phi_3)/bb)); float theta22_1 = acos((( A_1 * A_1)+(B_1 * B_I)-(a*a) -(alpha_1*alpha_1))/ (2.0 * a * alpha_1)); float theta22_2 =acos((( A_2 * A_2)+(B_2 *B_2) -(a* a) -(alpha_2*alpha_2))/ (2.0 * a* alpha_2)); float theta22_3 =acos((( A_3 * A_3)+(B_3 * B_3) -(a*a) - (alpha_3*alpha_3))/ (2.0 *a* alpha_3)); double theta11_1 = atan2( ((B_1 * A_1) - (EE_1 * a) - (EE_1 * DD_1)) / ((A_1 * a) - ( EE_1 * B_1) + (DD_1 * A_1)), ((B_1 * B_1) - ((a + DD_1)*(a + DD_1))) / ((EE_1 * B_1) - ( A_1 * ( a + DD_1))) ); double theta11_2 = atan2( ((B_2 * A_2) - (EE_2 * a) - (EE_2 * DD_2)) / ((A_2 * a) - ( EE_2 * B_2) + (DD_2 * A_2)), ((B_2 * B_2) - ((a + DD_2)*(a + DD_2))) / ((EE_2 * B_2) - ( A_2 * ( a + DD_2))) ); double theta11_3 = atan2( ((B_3 * A_3) - (EE_3 * a) - (EE_3 * DD_3)) / ((A_3 * a) - ( EE_3 * B_3) + (DD_3 * A_3)), ((B_3 * B_3) - ((a + DD_3)*(a + DD_3))) / ((EE_3 * B_3) - ( A_3 * ( a + DD_3))) );

Computing Jacobian

Computing Gravity Compensation

Chart